#include<string.h>

char *oddString(char **words, int wordsSize)
{
    int len = strlen(words[0]) - 1;
    for (int i = 0; i < len; i++)
    {
        int temp = words[0][i + 1] - words[0][i];
        if (temp != words[1][i + 1] - words[1][i] && temp != words[2][i + 1] - words[2][i])
        {
            return words[0];
        }
        for (int j = 1; j < wordsSize; j++)
        {
            if (words[j][i + 1] - words[j][i] != temp)
            {
                return words[j];
            }
        }
    }
    return NULL;
}